Method and apparatus for forming hollow ware



' 1,6 1,496 June 7', 1927. H. LUNDGREN 3 METHOD A ND APPARATUS FOR FORMING HOLLOW WARE Original med March 16,1921 5 sheets-sheet 1 Inifeniio ELun en e/Me A 1927. June LU'NDGREN METHOD AND APPARATUS FOR FORMING HOLLOW WARE ri inal Filed March 16,1921

5 Sheets-Sheet 2 lai /(2211522 B JiLuWren .FiytZ.

June 7, 1927.

. 1,631,496 LUNDGREN METHOD AND APPARATUS FOR FORMING HOLLbW WARE Original Filed March 16 1921 5 Sheets-Sheet 3 lays.

Ina/auto JI-Lu an 101 .gm ML 1,631,496 June 7 1 H. LUNDGREN ammo AND Armmus won FORMING HOLLOW WARE I Original Filed 16, 1921 s Sheets-Sheet 4 1 n June 927 H. LUNDGREN METHOD AND APPARATUS FOR FORMING HQLLQW WARE Original Filed March 16. 192! 5 Sheets-Sheet 5 n V W WW w Aw \V w $N w gm NM NW m as Q 3 N aH h ofjthe" die back 2. I V ithe'ribs are equally spaced and extend trans- In the machine here disclosed it is possible to obtain. a maximum extraction of moisture from the pulp during the forming operation.

This is brought about by the manner in which pressure is exerted-upon the dies and also the detailed formation of the dies asshown in Figs-5 and 6. s

It will thus be seen that the pressure faces are represented by perforated Walls 27,

These walls are mounted on arcuate-ribs 28 As shown in Fig. 5

versely of the bacln It is also desirable to incline them, at a slight angle so that suitable drainage will be brought about. Out- =let duets 30 are formed through the back plate and communicate with the grooves between the ribs. This will make it possible to carry off the moistureextracted by the pressure of the pulp.

' The bottom of the container in the present instance is formed'integral with the body portion thereof, andforthatpurpose a per forated bottom die 31 is reciproeably mounted'beneath the dies and 26 and to operate with the end of the core 18 to exert pressure 7 upon the pulpy materialtherebetween.

'Movement of the dies 25 and 26 is brought about by a series of plunger rods 32, which extend through vertical bearings 33 in the bottom o'ftlie moldlhousingw. The lower ends of these rods are formed with bearing yokes to receive cam rollers 34. The upper ends of the rods are pivoted to links 35,

which linksare secured at their upper ends to pressure rods 86, are 1117' Vertical alignment, and are disposed above the. plunger .rods 32. T0 is links 37 are i ivoted to ins 38, car ied at the oppositesi des of said rods,

.one set of said pins being disposed at the 7 upper end of ai'od and the other nearthe lower end thereof.

nc toggle links extend in opposite directions from the rod, one

set connected by a pivot 39 with the back plate 21 of a-die. The opposite set is secured by its outeren'd to pivot pins 40 car ried by the mold housing 19. As shown in Fig. 4, oppositely extending toggle links are (lisposed above and below the extension .22. of each of the the back plates, and in equal spaced relation to this extension. i By ver- ,tieal reciprocation of the pressure rod 36 it will thus be possible to swing the links in a manner to. advance and retract the dies in a. horizontalplane and to directly The lower die 31 is mounted .within a cylindrical case 41, disposed beneath the center of the mold. This case is formed with a central downwardly extending-bearing" portion receiving a plunger; 42 .fitted .withj av cam roller '34 as previously described for the plungers 32. Shoulders are formed upon each of the plungers 32 and 42 to provide a surface against which expansion springs V and'uni fornily apply pressure to the dies.'-

43 may act. These springs will at'all times tend to hold the plungers in their lowermost positions, and the rollers against cam tracksv to be hereinafter described; V

The pressure of the various dies is brought about by movement of the plunger rods 32 and 42 as their rollers-34pass along cam tracks 44. Five of these tracks are arranged concentric round the center'piii 12 and upon the base. 10, and thus actuate the four plunger rods 32 of the dies for each mold and the central plungerrod 42 for the bot- 'ton die of each mold. Eachof the tracks is formed with a series of swells as indicated.

in Fig. 7. The first swells A are of short duration and tend to' force the die members in around thecore to initially work thepulp and distribute it to form a container wall of uniform thickness' Thesecond. set of swells B gradually force the die members in, and thereafter-release the pressure on the dies; There are a plurality of the swells B which act to work pulp and produce a 'iho ugh extraction of the moisture there ends of vertically slidablespindles 45..

These spindles are formed with key ways 46, receiving splines carried on the star lllt wheels 47, which operate to intermittently rotate the spindles and the cores at certain intervals during action of the machine. The

star, wheels are mounted on the upper face of the spider 13 and are held against longitudinal movement relative to their spindles by the bases of supporting brackets 48. These brackets extend vertically and guide the upper ends49 of the core spindles.

The core spindles are adapted to belreciproeated in synclironisin with the movement of the turntable and the various molds. This reciprocating action is brought about by cam tracks 50 which are secured to a fixed cam frame 51. As shownin'Fig. 1 a rise is made, 111' the cam track to support a die,

while it is passing a filling station, and to thereafter permit the die to be lowered into the mold as the turntable moves one-eighth of a revolution. The lifting act-ion is brought. aboutby engagement of cam rollers 52 with the track.

The intermittentrotation of the dies relative to their longitudinal axes is brought about by pins 58, which are stationed at in tervals of one-eighth of the circumference of the member 51 to be engaged by teeth of the star wheels 47, thus rotating the star wheels and the dies.

, gara e 7 Referrin'g to Fig. 4, it will b'e not'ed that the lower ends o't'the Spinal-e345 are formed withshoulders54L a short distance above the upper faces of the cores. The spindle is then-reducedm diameter to pass through a cover plate 55 This cover plate'is held against the shoulder '54 by an expansion spring56'. The body' portion of the cover plate'is circular, and snuglyfirs within the mouth 57 of'rnold plate 58. A lipj59" of re duced diameter is tormedat the lowerfedge oi": the cover plate and inthe present instance provides an" annular rec'essat' the mouth of the container being formed. The'upper' end of the d'ie slid es' within a central bore of the plate;

Pulp is fed into the molds autbriiatically as they reach a' feeding posit-ion indicated in the present-instance as directlyin alignment with the spur driving gear 14". This-means n'ism coniprises" a" measuringdevice 59* in coiiin'iunication with a supply of; pulp through an inlet spout 60, The measuring means consistsot a cir'cular case 61- disposed with its central axis horizontal andrceiying' a" rotating" measuring "valve 62 This-valve is formed with acentral recess63 norinally turned upwardly to irceive'a'sup aly' of pulp from the inlet nieriiber 60. 'Thevawema be' rotated a gear 64 secured to'a spindle, which spindle extends through the center of the valve. A vertically moving rack 6'5"-'is in rneshwith the gear 6i andis-slidabl'y supported in a vertical guide member 66."- The lower end of this rack carries a roller 67 which may successively ride over cam members 68'. As shown in Fig. 1 these'caniniefiihers are disposed adjacent the va'riou'smolds are fixed to the turiitableso that as each of the molds passes the feed mechanism; a

and

feed'cain willlift the member 66 thereby rotating the valve 61 andca'usingthe'cavity therein to turn downwardly and duinp the pulp into a feed spout 69. Ret'erring'to Fig. 7, it will be seen that this spout directly coirveys the pulpinto the mouth 57 of the iiiold.

The operation, broadly considered, con

sists in successively pressing a mold w'ithits dies retracted to the teed1neans,-where a measured quantity of semi-solid ulp will be placed in theinold, after which the core will be, projected into the, mold. At this time the dies will initially move in around the core, thereafter retracting and moving in around the core as theni'old proceeds,

while between each coriipressioh' the dieis rotated one-eighth of a turn without being wit urawrrrrem the nioldf The pressure exerted upon the pulp by the dies will" be progressively prolonged in its duration, after'whichthe wall or theeoritainers will be-- stretched and the I coiitairi'ers thereafter removed from the niold and the die.

By reference toFigl 2 it will-be evident that there" Ihight be eight Stiifi Oil 6 0F 5 tion in the prese'nt machine; as: there are eight niolds "disposed around the circular turruabiei The nuniber ot station are; however--,;fdtermined by-f the 'saituratio1i 0f the pulp with moisture, th enatur'e of the pulp, and'the diflicultyin producing a desirediextraction of'th'e moisturetherefrom. In any event it is' assiiin'ed that thevarious sets of camsBshall'be successively lengthened; so thatfeach -eorhpressionoperation will be prolonged-and the moisture gradually and firmly torc'ed'trorn'the pulp. Assum'ingthat station- 1' is" represented by the position of the pulp feeding mechanism, a mold will pass tothis' station, at which time the feed ca1n 68 associated with that particular mold will encounter the feed rod 65, forcing up a a on this rod and rotating the measuring 1116111 device may be durnped into the feed' spout I and thereafter conveyed into the o'penj mold; As thisfille'd niold' moves tothe second star tron, represented by one-eighth of a r'evol'u tion" of the turntab1e;:the the lifting mold 52- will'ericounter the inclined portionof the c'ain' 50,?andthe core 18 corresponding to the particular rn'old' will be" gradually lowered into' thefilled-"mold; As "thislowering action proceeds thefille'r' plate--55-Lwi1l follow the core ithrough the"opening 57g thereafter fitting; snugly therein to prevent the pulptroni forcingout. As the'rollers'34 'of the plunger rods 321and thepulp'by the; dles. This pressure, as-"will be understood,- is brought about byupward movement of the plungers 31 against their links 85, thereafter swinging the pressure 36"to"for'ce'-th'e" pressure links into horizentarah nme e and thus produce a "considerable ressure; upon' the dies asc'they 452 encounter the first set ofcalns A, short-initial re'ssurewillbe'exerted on V simultaneously" Iriove inwardlyaround the core. As reviousl described, the diesare so formed that their'uniforIn-Inovement'wrll cause ther'ri' to continuously produce a closed lengths of the successive sets of these cams so that more "perfect extraction of moisture can 'be brought about? Between pressure intervals the star wheel will" encounter pins "53, which'willrotate 'the core" a portion of a r'e iOlutiQiiandwillithus cooperate with At this &

the core, and thedies. to work the pulp and thoroughly subject all of the container wall ofthe dies and willfinally drain into a-basin- 70disposed beneath the dies. A drain pipe 71 is connectedwith the various basins.

'Duringrthe simultaneous advance and retraction of the horizontally moving dies the plunger42 will move to force a pressure plate 72 against the bottom die 31 and form the closed end of the container. Liquid ex. tracted from this portion of the container may drain out through a duct 7 3.,

When the last set of extraction cams B have been passed the pair of dies 26 is then I forced inwardly by the cams C, which acby the star wheel when it encounters one of tion will tend to slightly stretch the fiber of the container wall and distortthe same in I the direction of the dies 25. Rotation of the core and the container is then brought about pins 58. This will stretch the wall of the container to a larger diameter'thanthe core. The core may then be readily removed and the container withdrawn from the mold. The wall of the container is then fairly free from moisture so that it may be readily dried under normal ,atmospherical conditions. If, i however, itis deslred to hasten the drylng,

the containersmay be placed, in'a suitable oven- In the event that other sized containers are used, the cores may be removed from their spindles, and the dies readily removed from-the pressure blocks due to their dove-tailed connection therewith.

It will thus be seen; that a very compact machine is hereby disclosed, the construction being such as to insure that a maximum extraction of moisture from the pulp may .be made without breaking the fibers of the pulp, at the same time insuringthat the containermay be removed from the mold and the die without difficulty.

While I have shown the preferred form of my invention as now known to me, it will be understood that "various changes might be made in the combination, construction andarrangement of'parts by those skilled in the art, without departing from the spirit of theinvention, as claimed. 7 v

-Having thus described my invention, what I- claim and desire to secure by Letters Patent is: V

1. A method of making containers from plastic material, which consists in distributing the material over the outer surface of a rigidcore, and thereafter molding the material by intermittently exerting pressure thereagainst and uniformly around the core,

and then stretching the material tovloosen the container thus form-ed from the core.

2. A method of forming containers from plastic material, which consists in applying said mater al to the outer surface of a rigid upon the formed container thereon between intervals of core and then gradually compressing and work ng the material agalnst the core by intermittent and progressively increased rigid core and then gradually compressing and workingthe material against the core by intermittent and progressively increased pressure action by the mold members exerting pressure uniformly against the core and changing their position relative thereto as a the molding proceeds.

4. A method of. forming containers from plastic material, which consists in applying said material to the outer surface of a rigid core and then gradually compressing and working the inaterialagainstthe core by intermittent and progressively increased pressure action by the mold members exerting pressure uniformly againstthe core and changing theirposition relative thereto as the molding vproceeds, thereafter acting a to slightly 'stretch'its Wall andto thus separate it from its core. V r

5. The process of making paper hollow ware which consists in intermittently pressing paper pulp between. a core and mold ,members to form the hollow. ware, and

thereafter exerting pressure upon the wall thereof to slightly stretch the same circumferentially and to thus separate the hollow after inserting a core into the mold and the pulp to -distribute the pulp over the bottom and around the side of the core, then intermittently and uniformly exerting pressure. between the core and the sections of the mold to shape the wall of the container and extract the moisture therefrom, and then exerting pressure by mold sections to stretch the wall of. the container circumferentially and loosen it from its core.

7. A process of making containers from pulpy material which consists in placing a measured amount of paper pulp within a sectional mold, thereafter inserting a core within the mold to displace a portion of the pulp anddistribute it over the bottom and around the sides of the core, then intermittently exerting. pressure vupon the pulp by the mold sections and intermittently rotat ing the core and the container being formed pressure by the mold. I

8. A process of making containers from pulpy material which consists in placing a .measured amountof paper pulp within a sectional mold, thereafter inserting a core within the mold to displace a portion of the pulp and a distribute it over;

- 1 tently exertingpressure upon the pulp by the mold sections} and intermittently rot'ate' ing the core "and the containerfbeing rbr'medf thereon between intervals; of pressure by the mold, said rotation. representing a fraction". 7 ofa revolution of. the core. i

,9 A process ofmal:ing magne s from pulpy material, which consists; in plac ng a measured amount of paper pulp within a 1 within the mold. to; displacea portionof 'the pulp and distributeit over the bottom and around the sides of the core, then intermittently exerting pressure upon the pulp by the: mold sections and intermittently rotat-; ing tliecore and the "container being formed tliereon between intervals of pressure by the mold, and then-exerting pressure upon thediametrically opposite sides of the container Wall to stretch the same circumferentially and separate it from the core.

10. The process of forming containers from paper pulp, which consists in placing a measured amount of paper pulp in a sectional mold, thereafter inserting asolid core into the mold and the pulp to distribute the pulp to form a container having a bottom and a circumferential side wall, then simultaneously and uniformly exerting pressure directly against the pulp at. theend of the core and radially against the pulp around the sides of the core, then repeating said operation with progressively prolonged'intervals of pressure. V

11; The process of forming c'ontamers from paper pulp, whichconsists in placing a'measured amount of paper pulp in a sectional mold, thereafter inserting a solid core into the mold and the pulp to distribute the pulp to form a container having a bottom and a circumferential side wall, then simultaneously and uniformly exerting pressure directly against the pulp at the end ofthe core andvradially against the pulp around the sides of the core, then repeating said operation with progressively prolongedimtervals of pressure, and partially rotating the container between the intervals of pressure.

12. The process of forming containers from paper pulp, which consists in placing a measured amount of paper pulp in asectional mold, thereafter inserting a solid core into the mold and the pulp to distribute the pulp to form a container having a bottom and a circumferential side wall, then simultaneously and uniformly exerting pressure directly against the pulp at the end of the core and radially against the pulp around the sides of the core, then repeating said operation with progressively prolonged intervals of pressure, and partially rotating the container between the intervals of presthe bo tomfand around; the sides: of the core, then'Ti'ntermitsectional mold, 4 thereafter inserting. a. core sure,v and then exerting pressure by certain I the core, and means for. partially rotating, so

the": container being? formed betive'en inter='- vals'of pressure? :14. A machine 'forf"producing "containers nan "papenipulp, comprising horizontally movable sectional molds, into which paper ulp is (placed, verticallym'ovable; cores adapted to" be projected intosaid molds, means 'for simultaneously and intermittently creating pressure between the sections of the mold and the core as the said mold and core travel, and means for partially rotating the 9,0 corejand the container bemgformed' thereon betweenintervals of pressure exerted by the Y moldsections; V a

15. A machine for producing containers; from paper pulp, comprisingvertically movable cores adapted tobejprojectedinto said molds, means for simultaneously and inter mittently creating'pressurebetween the sections of the mold and the core as the said ;mold andcore travel, means for partially" rotating the core and the container being formed thereon between intervals of presv sure exerted by the mold sections, and'means' for stretching the wall of the container cir- '7 cumferentially atthe conclusion'of the pr.essure forming operations of the; mold."

16. A machine forproducing containers from paper pulp;comprising'vertically movable cores adapted to-be projected into said molds, means for simultaneously andinter mittently'creating pressure between thesections ofthe mold and the core as the said, mold andcore travel, means for partially rotating the core and "the container being formed thereon between intervals ofpressure exerted'by the mold sections, means for stretching the wall of the container circumfor automatically withdrawing the core from the mold.

17 Amachine forforming paper hollow ware, comprising a" continuously rotating table, a plurality of contracting mold units mounted upon said table, a plurality'of cores, one forrea'ch of said units, said cores and. molds moving in unison, means for sucy c-essiv-ely exerting uniform pressure by the mold agalnst plastic material distributed" over the surface of the core asthe table eroferentially at the conclusion of the pressure forming operations of the mold, andmeans tetes,"andfm;eenls for stretching the container hetivveenthe arious mold sections and the core at'intermittent periods'end means for, progresslvely prolongingsaid periods of.

pressure.

3 19. A method plastic material, which consists in'disposing' the material-around a eore thereafter exerting pressure against the niat'erialand core ,0 formn container and torelnove theliqof, making containers fi'ron f uid contentiof the' ma terial; and thereafter" exerting pressure against diametrically opformed to loosen 'it from the core.

i 20.. A method of making containersj 'from plastic material, which consists in disposing the" material-around a core, thereafter intermittently exerting pressure against; the ma 'terial and core to form a container, said-in tervals of pressure being progressively prolonged to remove the liquid from the material, and thereafter intermittently exerting pressure to diametrically opposite points aroundthe'container to loosen it froin the core.

HARRY: LUND GREN.

Y posite points around the container thus :20 

